Electronic communication products which transmit and receive radio frequency (RF) signals need to match the impedances between the internal circuitry, such as an RF power amplifier, and the antenna for optimum performance of the product. The optimum mode may also depend upon the modulation scheme, the frequency of transmission and other considerations.
Electronically tunable filters are frequently used to compensate for any impedance mismatch between the circuitry and the antenna. Such tunable filters utilize various tuning elements, such as tunable capacitors, varactors, micro-electronic mechanical systems (MEMS), and doped semiconductor materials.
Adaptive impedance matching modules (AIMMs) sense continually sense impedance mismatch and retune the impedance for any changed conditions. AIMMs may take up to 20 iterative steps to converge on the best impedance match, such as by using gradient search methods.
There is a need for an adaptive impedance matching network which can rapidly tune to the best or optimum matching impedance in fewer steps and in less time.